Apparatus for raising and lowering a heavy weight

ABSTRACT

Apparatus for raising and lowering a heavy weight such as working platform along a column which also may raise and lower the column in the floating condition of the working platform in the same efficiency as the operation in the working platform. To this end, the apparatus is so constructed that main cylinder for raising and lowering the working platform and column is always actuated to push out the associated piston rod for moving the working platform or the column.

United States Patent Izumi Mar. 11, 1975 APPARATUS FOR RAISING AND LOWERING A HEAVY WEIGHT [75] Inventor: Hitoshi Izumi, Yokohamashi, Japan [73] As'signee: Mitsui Shipbuilding and Engineering Co. Ltd., Tokyo, Japan [22] Filed: May 7, 1974 [21] Appl. No: 467,780

[30] Foreign Application Priority Data May 10. 1973 Japan 48/51'910 [52] US. Cl. ..-182/l36, 182/187 [51] Int. Cl. E04g 3/02 [58] Field of Search 182/136, 187, 141,148,

[56] References Cited UNITED STATES PATENTS 1,964,995 7/1934 McLaughlin 182/136 2,906,365 9/1959 Howard 182/136 2,947,148 8/1960 Young 3,028,143 4/1962 Chcskin 182/133 Primary ExaminerReinaldo P. Machado. Attorney, Agent, or FirmHowson and Howson; Albert J. Free [57] ABSTRACT Apparatus for raising and lowering a heavy weight such as working platform along a column which also may raise and lower the'column in the floating condition of the working platform in the same efficiency as the operation in the working platform. To this end, the apparatus is so constructed that main cylinder for raising and lowering the working platform and column is always actuated to push out the associated piston rod for moving the working platform or the column.

1 Claim, 11 Drawing Figures PATENIED MARI 1 1975 SHEET 2 Di: 2

1 APPARATUS FOR RAISING AND LOWERING A HEAVY WEIGHT i The present invention relates to an apparatus for raising and lowering a heavy weight such as a working plaform.

The object of the present invention is to provide an apparatus which can raise and lower a floatable working'platform along a column piled in the sea bottom and also can raise and lower the column in the floating condition of the working platform. 1

1 Another object of the present invention is to provide an apparatus in which raising and lowering operation of the column may be performed in the same efficiency as the operation in the working platform.

Other objects and advantages of the. present invention will become apparent from the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a plan view of an apparatus according to the present invention, with the left half portion of the drawing showing a top plan view of the lower outer ring and the right half portion showing a .top plan view of the upper outer ring;

FIG. 2 is a sectional view taken along the line A-A of FIG. 1;

FIG. 3 is a sectional view taken along the line 8-8 of FIG. 1;

FIGS.'4a and 4b are diagrammatic drawings illustrating the column raising operation according to the present invention;

- FIGS..5a to Sfare diagrammatic drawings illustrating the column lowering operation according to the present invention.

Referring to the drawings and more particularly to FIGS. 1 to 3, the apparatus according to the present in- 7 on the ring 1 by means of oil hydraulic cylinders 6,

The lower wedges 8 are held in the frame 28, which is Each inverted wedge 18 is engaged with the inner inverted tapered periphery of the block 16 and held by a frame 20. Each inverted wedge 22 is engaged with the inner inverted tapered periphery of the block 17 and held by a frame 24. The frame 20 is connected to the oil hydraulic cylinder 21 and a pair of legs of the frame are slidably engaged with guide members 26 provided on both sides of theblock 16. The frame 24 is also connected to the oil hydraulic cylinder 25 and a pair of legs are slidably engaged with guide members 27 provided on both sides of the block 17.

Describing now the operation of raising of the column, the oil hydraylic cylinders 6 and 10 are extended to lower the frames 5 and 28 thereby the wedges 3 and 8 are not engaged with the rings 1 and 2. i

In the'condition of FIG. 4b, the hydraulic pressure circuits of both upper and lower inverted wedge operating cylinders 21 and 25 are left inoperative, and hence the upper and lower inverted wedges 18 and 22 are engaged with the column and blocks 16 and l 7,by their own weight-The working plaform I is floating on the sea, and the weight of the apparatus is transmitted to the working platform I through the lower outer ring 2, step portions of tie rods 13 and tie rod connecting pins 15. Under this condition, the piston rod of each main cylinder 12 is extended to the limit of the stroke, whereby upper inverted wedge 18 is brought into the perfect wedging engagement with the tapered surface of the block 16 to grip the column II, thus the column is rise with the'upper outer ring 1 (FIG. 4a). Then each main cylinder 12 is contracted from the position of FIG. 4a whereby the upper outer ring 1 is urged to descend,'as the descent of the column II, the lower inverted wedges 22 are brought into a perfect wedging engagement with blocks 17 to grip the column II, and hence descent of the column II is stopped. Thus only the upper outer ring 1 is lowered (FIG. 4b). The above operation-is repeated cyclically to raise up the column II.

Lowering operation of the column is as follows. In the condition of FIG. 5a, the column II is gripped by the lower inverted wedges 22, and the upper inverted wedges 18.are withdrawn from engagement with the column, while each main cylinder is in its completely contracted state. In operation, each main cylinder 12 is extended from the condition of FIG. 5a. Before the cylinder 12 reaches to the stroke end (FIG. 5b), the

also suspended from posts 11 on the ring 2 by means of oil hydraulic cylinders 10.

Each post 7 has a guide surface to maintain the clearance between the column and-upper and lower rings within a certain permissible range. Between the rings 1 and 2 main oil hydraulic cylinders 12 are provided. The working platform I is connected to the upper ring 1 by tie rods 13 each of which is passed through a hole of each ring and connected to the working platform by a pin 15 and a nut 14 is engaged with the top of the tie rod 13. Each rod 13 has a larger diameter portion at the lower part thereof with which the lower ring 2 is engaged and thereby held. Arrangement by rings 1 and 2 and wedges '3 and 8 is to raise and lower the working platform I along the column secured on the sea bottom.

Arrangement for raising and lowering the column II comprises inverted taper blocks 16 secured on the upper ring 1, inverted taper blocks 17 secured on the lower ring 2, inverted wedges l8 and 22, friction materials 19 and 23 and oil hydraulic cylinders 21 and 25.

upper inverted wedge operating cylinder 21 is contracted to bring the upper inverted wedges 18 into the wedging engagement with the column. Simultaneously, pressure oil is introduced in the chamber of each lower inverted wedge operating cylinder 25 to urge the lower inverted wedges 22 upwardly. However, the lower inverted wedges are not withdrawn from the wedging engagement with the column, because the column weight is loaded to the lower inverted wedges 22 (FIG. 50). Then each cylinder 12 is extended to the stroke end, whereby the upper inverted wedge 18 is brought into the wedging engagement, so that the column II is rised slightly with the upper outer ring 1. Thus the lower inverted wedges 22 is released and moved away from engagement with the column by the lower inverted wedge operating cylinder 25 (FIG. 5d). The main cylinder 12 is then contracted from the position of FIG. 5d, whereby the column II is now gripped by the upper inverted wedges 18 and lowered with the upper outer ring 1. Before the main cylinder 12 reaches to the stroke end (FIG. 5e), pressure oil is fed into the lower inverted wedge operating cylinder 25 to force the lower inverted wedges 22 into engagement with the column. Concurrently with this, pressure oil is also introduced into the upper inverted wedge operating cylinder 21 to force the upper inverted wedges 18 upwardly (FIG. 5 The main cylinder 12 is further contracted to the stroke end, whereby the lower inverted wedges 22 are brought into wedging engagement to grip'the column ll, thus the column is stopped. Since the upper outer ring 1 keeps on descending, the upper inverted wedges 18 is released and the upper inverted wedge operating cylinder 21 is extended to the stroke end to raise the upper inverted wedges 18 (H0. 5a). The above mentioned operation is repeated to lower the column II.

From the foregoing, it will be understood that column lifting is accomplished by moving up or down the upper outer ring 1 by the opertion of main cylinder 12 supported by the lower outer ring 2 which is engaged with the step of the lower part of each tie rod 13. Ascent of the column is effected by extending the main cylinder 12. Since area of the outside surface of the piston is larger than area of the rod side surface of the piston, extending force of the piston rod is greater than contracting force of the piston rod. Therefore the operation of the main cylinder 12 in ascent of the column is very advantageous as strong thrust is obtained for extracting a column piled into the sea bed. The tie rod 13 receives compression force when the column is raised or lowered, but the distance between the portion of the tie rod which receives such compression force and the tie rod connecting pin 15 is relatively short. This short distance proves extremely advantageous with regard to buckling of the tie rod. Further, since the tie rod is slidably engaged with both upper and lower outer rings, kink of the apparatus, that could possibly take place, is minimized.

For raising the working platform, both upper and lower inverted wedge operating cylinders 21 and 25 are extended, so that the upper and lower inverted wedges l8 and 22 are moved away from the engagement with the column, while the upper and lower wedges 3 and 8 are operated to be brought into wedging engagement with the column. Under this condition, the main cylinder 12 is extended or contracted. During the working platform lifting operation, weight of the working platform acts always downwardly against the tie rod 13, so that the upper face of the upper outerring l and the nut 14 are kept closely attached to each other.

What is claimed is:

1. Apparatus for raising and lowering a heavy weight comprising a column, a floatable working platform adapted to be moved along said column, an upper outer ring surrounding said column, a lower outer ring surrounding said column and having a spaced distance from said upper outer ring, each of said outer rings having a tapered inner surface, a' plurality of upper and lower wedges each of which has a tapered outer surface which may be engaged with the corresponding tapered surface of either of said outer rings, frames for holding said upper and lower wedges, several cylinders for operating said wedges, upper and lower inverted tapered blocks disposed on said upper and lower outer rings respectively, upper and lower inverted tapered wedges which may be engaged with the corresponding tapered surfaces of said inverted tapered blocks, frames for holding said upper and lower inverted wedges, cylinders for operating said upper and lower inverted wedges, guide means for moving said upper and lower inverted wedge holding frames in the direction parallel to the inverted tapered surface, main cylinders coupling said upper and lower outer rings and adapted to move said working platform and column, and tie rods passing through the upper and lower outer rings and connected to the working platform with the top end of said tie rod being projected, each said tie rod having means for preventing the upper outer ring from removing from the tie rod at the top end and having a step portion for receiving the lower outer ring. 

1. Apparatus for raising and lowering a heavy weight comprising a column, a floatable working platform adapted to be moved along said column, an upper outer ring surrounding said column, a lower outer ring surrounding said column and having a spaced distance from said upper outer ring, each of said outer rings having a tapered inner surface, a plurality of upper and lower wedges each of which has a tapered outer surface which may be engaged with the corresponding tapered surface of either of said outer rings, frames for holding said upper and lower wedges, several cylinders for operating said wedges, upper and lower inverted tapered blocks disposed on said upper and lower outer rings respectively, upper and lower inverted tapered wedges which may be engaged with the corresponding tapered surfaces of said inverted tapered blocks, frames for holding said upper and lower inverted wedges, cylinders for operating said upper and lower inverted wedges, guide means for moving said upper and lower inverted wedge holding frames in the direction parallel to the inverted tapered surface, main cylinders coupling said upper and lower outer rings and adapted to move said working platform and column, and tie rods passing through the upper and lower outer rings and connected to the working platform with the top end of said tie rod being projected, each said tie rod having means for preventing the upper outer ring from removing from the tie rod at the top end and having a step portion for receiving the lower outer ring. 